Chaotic transients in the switching of roto-breathers

By integrating a set of model equations for Josephson ladders subjected to a uniform transverse bias current we have found almost all of the kinds of breathers described in recent experiments, and closely reproduced their vol tage-current characteristics and switching behaviour. Our main result is th at a chaotic transient occurs in the switching process. The growth of tiny perturbations during the chaotic transient causes the new breather configur ation to be extremely sensitive to the precise history of the initial breat her and can also cause the new breather to have a new centre of symmetry. ( C) 2001 Elsevier Science B.V. All rights reserved.